Today in the world, one can distinguish two different technologies for maintaining water bodies.
On the one hand, one can distinguish conventional swimming pool water treatment technologies, which will be referred to as “Technology A”. On the other hand, one can distinguish an innovative water treatment technology for treating and maintaining large artificial water bodies, such as large artificial water bodies, which will be referred to as “Technology B”. Both technologies are very different in nature, operation, configuration, and size, and are directed at very different objectives and water body types, and therefore the suctioning devices used for each technology are completely different.
Technology A, which refers to conventional swimming pool treatment technology, is used in small and confined water bodies with specific characteristics and usually built out of concrete with plain, regular, and firm bottoms. Since swimming pools have low sizes, their regulations require filtering the complete water body between 1 and 6 times per day to maintain a suitable water quality for recreational purposes.
Technology B, on the other hand, allows treating and maintaining large water bodies that have irregular and soft bottoms built of out plastic liners, and where such water is treated though efficient flocculation that allows precipitating impurities, and afterwards removing the settled impurities and debris from the irregular and unfirm bottoms, especially the flocs that are formed in the water treatment process, thus avoiding the use of conventional centralized filtration systems and conventional swimming pool technologies such as Technology A.
Swimming pools using Technology A generally use conventional swimming pool bottom cleaners, and there are many different types and models within the market, which have been specially designed to clean the bottom of relatively small recreational water bodies such as swimming pools, among other applications. Such pool cleaners are configured to clean small surfaces, and therefore their surface cleaning rates (i.e., the amount of bottom surface cleaned in a predetermined period of time) are low and would not be practical for cleaning the bottom of large artificial water bodies using the Technology B due to their large sizes.
Also, such cleaning devices are configured to clean smooth surfaces that do not present irregularities or bumps. For example, typical swimming pools are built out of concrete, fiberglass, or other materials that may be coated to provide a firm, plain, regular, and smooth surface. Therefore, such surfaces can be easily cleaned by conventional pool bottom cleaning devices. These conventional pool bottom cleaning devices are therefore not designed to clean soft and irregular surfaces such as the bottom of large artificial water bodies using Technology B, as the operation would be extremely inefficient and may even damage the bottom.
It must also be noted that the conventional swimming pool cleaners generally are provided with small suction heads, usually with scrubbers. The scrubbers are typically moved from the perimeter of the pool by rods or poles. This is possible due to the small surfaces that must be covered. These conventional cleaners are designed to remove the attached debris and stains found on the bottom and walls of the swimming pools. However, even though the small suction heads remove the debris from the bottom of the pool, the conventional centralized filtration system of the swimming pool must still be used to treat the contaminations suspended in the water, where the conventional filtration system filters the complete water body from 1 to 6 times per day to purify the water.
Also, many of such devices for swimming pools using Technology A utilize rotating brushes, scrubbers or other systems that may cause the flocs to disperse and/or re-suspend, and also may comprise filters attached to the suctioning devices, which is not applicable to large artificial water bodies using Technology B due to the large water volumes that must be filtered.
Conventional pool cleaning devices are typically permanently supported by a series of wheels, which although have little or no impact on the bottom surface of conventional pools (typically formed from concrete, fiberglass, or other materials that may be coated to provide a firm, plain, regular, and smooth surface), can damage the bottom liner of water bodies using Technology B since the bottom has irregular surfaces and therefore the wheels could cause undesired stresses including, for example, stretching and folding of the material of the liner. Additionally, if a sharp object, such as a stick, rock or other debris is located above or below the plastic liners, the weight/pressure caused by the wheels could cause the liner to puncture, causing damage and leaking of the water.
Moreover, as a result of the irregular surfaces present (i.e., areas or zones that have higher or lower depths), they cannot be cleaned properly through such conventional bottom cleaners. Additionally, the conventional bottom suction cleaners used in Technology A cannot work at high speeds. As a sediment cloud is lifted by such devices, suctioning all of the bottom layer sediments is nearly impossible. The sediment cloud causes mixing and turbulence on the bottom layer of the water body, reducing sedimentation capacity and thus not allowing to properly treating the water body.
TABLE 1Differences between Technology A and Technology BTechnology BTechnology ALarge ArtificialFeaturesSmall Swimming PoolsWater BodiesAverage WaterGenerally 80 m2GenerallySurfaceOlympic Pool: 1,250 m230,000 m2-400,000 m2Bottom materialConcreteNatural terrain used asbottom, covered with plasticlinersBottom surfaceSmooth, regular, plain,Irregular, soft, withfirmprotrusionsWater treatmentPermanent high concen-Efficient flocculation thattration of chemicalsallows precipitatingimpurities into the bottomUses flocculantsOptionalMandatoryFiltrationUse of conventionalDoes not require acentralized filtrationcentralized filtration systemsystemUse of suctioningNo—small suctioningYes—the device allowsdevice fordevices are just used forremoving the flocculatedtreating theremoving attached debrisimpurities from the bottomwaterand stainsof the artificial water bodiesCleaning DeviceSlow operation due to theUse of fast propelling deviceOperationsmall sizes of swimmingdue to the large areas thatpoolsmust be coveredCleaning deviceRotating parts andNo rotating parts in order toscrubbers to detach debrisavoid re-suspension ofand stainsprecipitated material
Large water bodies using Technology B can be used for recreational purposes, such as for practicing water sports, bathing, and many other activities that allow improving the lifestyle of people around the world. Large water bodies can also be used for industrial purposes, such as for cooling purposes, drinking water storage and treatment, raw water storage, seawater treatment for reverse osmosis and mining applications, and many other applications.
Such large water bodies using the Technology B typically have irregular and soft bottoms. This often results from the positioning of a liner, often plastic, directly on a natural surface. The water contained in the large water bodies is often treated though, efficient flocculation that allows precipitating impurities, and afterwards removing the settled impurities from the irregular and soft bottoms, especially the flocs that are formed in the water treatment process, thus avoiding the need for conventional centralized filtration systems.
Conventional small devices for removing attached debris and stains from the bottom of conventional swimming pools using Technology A are not configured to clean large surface areas in short periods of time, and are also not configured to be propelled by a propelling device, such as a boat with an engine or a robotic system internally or externally connected to the device, since they are designed for small areas that do not present surface cleaning difficulties as the bottoms of conventional swimming pools using Technology A are usually built with concrete and are very regular and smooth.
One conventional suction device for Technology A comprises a suction head that can be moved along the lower surface of a swimming pool by an articulated rod by hand (therefore limiting the covered area and velocity of the cleaning process). Such device improves the service life of conventional suction heads that comprise bristles that are easily removed in order to be replaced in case they are worn out. Therefore, such suction device aims to replace worn bristles with unworn bristles so that the suction head's service life is no longer limited by the life of the occupied bristles.
Another conventional system for Technology A includes a vacuum head with parallel rows of brushes with a predetermined advancing direction and flexible foam for containing the water within the device in order to be suctioned. This device is designed to clean small swimming pools and provide an efficient suction due to the lock comprising flexible foam. However, this vacuum head is designed to clean regular (i.e., flat) bottoms of swimming pools, for example made of concrete, and not to cope with irregular bottoms as the ones from large artificial water bodies. Such a device includes a support plate to minimize the bending of the flexible foam, and a support wheel to provide stability to the device as it rolls along the surface to be cleaned.
Other devices include a suction head for conventional swimming pools using Technology A, having one central suction nozzle and an elongate main brush and auxiliary brushes to support the cleaning head, where the head is configured to move the debris into the central suction nozzle. This design causes re-suspension of debris since it has many openings within the suction head that just move and re-suspend the impurities instead. Such head is designed to be fitted into a conventional swimming pool vacuum cleaner, with a hand driven pole for moving the head, and a system to suction and filter the suctioned water within the same swimming pool, and therefore could not be used for large applications or for cleaning large surface areas in short periods of time.
Other types of vacuum heads for swimming pools using Technology A include a sphere-supported swimming pool suction head, comprising a plurality of rotatable spheres in base plate sockets to support the base plate above the pool floor. Therein, the suction head is maneuvered from the edge of the pool by a long pole. Although the base plate is a rectangular and flexible plate, the device is supported on rotatable spheres to provide a low rolling friction to aid handling ease, which is completely directed to solving the maneuverability issues from the border of the swimming pools. As this system is driven by hand within the perimeter, it could not be used for large applications or for cleaning large surface areas in short periods of time. Also, the rotatable spheres do not allow handling protrusions or irregularities in the bottom of large artificial water bodies, since they could damage the coatings from such large artificial water bodies.
Therefore, it must be noted that none of the suction cleaners used for operation in swimming pools according to Technology A would be useful or efficient for suctioning the bottom of large artificial water bodies using Technology B.
However, a few specific suction devices have been developed for use in large artificial water bodies according to Technology B, where such suctioning devices have presented many limitations associated with suctioning device speed, reversibility, turning capacity, suctioning efficiency, operation in irregular surfaces, and operation in sloped bottoms, among others.